ANGIOGRAPHIC CHANGES AFTER PIAL SYNANGIOSIS IN CHILDHOOD MOYAMOYA DISEASE

PURPOSE: To describe the angiographic changes accompanying the surgica l treatment of moyamoya disease by pial synangiosis and to compare the se changes with patient outcome; METHODS: The preoperative and postope rative cerebral angiograms, MR images, and clinical records of 13 chil dren treated with pial synangiosis for moyamoya disease were reviewed. RESULTS: After synangiosis, 10 patients had significant neurologic im provement and three had minimal or no improvement. Postoperative MR im ages showed no new infarctions. Well-developed (grade A or B) transpia l or transdural collaterals to the brain were present at the site of s ynangiosis in 84% of the surgically treated hemispheres. Cerebrovascul ar occlusive changes increased postoperatively in 76% of hemispheres. After synangiosis, moyamoya collaterals were increased in 48%, unchang ed in 16%, and decreased in 36% of surgically treated hemispheres. All 10 patients with grade A or B collaterals bilaterally after synangios is were asymptomatic or improved on follow-up. CONCLUSION: Pial synang iosis typically results in an increase in collaterals from the superfi cial temporal artery or middle meningeal artery to the brain. Synangio sis appears to result in stabilization or improvement in neurologic sy mptoms but does not prevent the angiographic progression of disease or the development of moyamoya collaterals. The angiographic demonstrati on of well-formed collaterals after synangiosis is associated with a f avorable clinical outcome.